EP0256594A2 - Data processing apparatus with energy saving clocking device - Google Patents
Data processing apparatus with energy saving clocking device Download PDFInfo
- Publication number
- EP0256594A2 EP0256594A2 EP87201486A EP87201486A EP0256594A2 EP 0256594 A2 EP0256594 A2 EP 0256594A2 EP 87201486 A EP87201486 A EP 87201486A EP 87201486 A EP87201486 A EP 87201486A EP 0256594 A2 EP0256594 A2 EP 0256594A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- data processing
- data
- signal
- processing apparatus
- reset
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000012545 processing Methods 0.000 title claims abstract description 84
- 238000005265 energy consumption Methods 0.000 claims abstract description 21
- 230000000694 effects Effects 0.000 claims description 4
- 230000007704 transition Effects 0.000 claims description 4
- 230000000903 blocking effect Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims description 2
- 230000006870 function Effects 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000021715 photosynthesis, light harvesting Effects 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
- G06F1/26—Power supply means, e.g. regulation thereof
- G06F1/32—Means for saving power
- G06F1/3203—Power management, i.e. event-based initiation of a power-saving mode
- G06F1/3234—Power saving characterised by the action undertaken
- G06F1/324—Power saving characterised by the action undertaken by lowering clock frequency
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
- G06F1/04—Generating or distributing clock signals or signals derived directly therefrom
- G06F1/08—Clock generators with changeable or programmable clock frequency
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
- G06F1/26—Power supply means, e.g. regulation thereof
- G06F1/32—Means for saving power
- G06F1/3203—Power management, i.e. event-based initiation of a power-saving mode
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D10/00—Energy efficient computing, e.g. low power processors, power management or thermal management
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/50—Reducing energy consumption in communication networks in wire-line communication networks, e.g. low power modes or reduced link rate
Definitions
- the invention relates to a data processing apparatus comprising: - a data processing element, having an operating mode and a stop mode, said element comprising a data input a first data output, a reset signal input, a clock input a stop signal output and first power supply terminal means; - oscillator means for feeding said clock input with clock pulses, said oscillator means having second power supply terminal means; - a data receiving module for receiving external data, said module having a second data output connected to the data input; wherein said data processing element has reset means for under combined control of a series of clock pulses and a reset signal on said reset input attaining an initial state within a predetermined line interval, the data processing apparatus being suited for economically consuming energy.
- Reducing energy consumption is of interest in environments of limited available power, e.g. in implanted medical devices, portable equipment or space satellites and in devices in which energy dissipation should be limited, e.g. in VLSI circuits.
- a first method for reducing energy consumption in a clocked data processing apparatus, designed in a low-power technology, would be to lower the frequency of the clock as far as possbile regarding the required data throughput. Problems then occur, in that DC-current paths, which can be hidden in the design of the data processing element, will be open for a longer period, thereby partially undoing this reduction, and also in that real-time processing may be no longer possible.
- a second method for reducing energy consumption would be to use a data processing element, having an operating mode and a mode of reduced activity, and to switch between these modes, keeping the element in the latter mode as long as no operating is required, in which mode the consuming of energy is less than in the former mode.
- a data processing element having an operating mode and modes of reduced activity is for example the single-chip 8-bit microcontroller PCB80C31, (Philips Data Handbook IC14N, 1985, pp.187-213).
- This element has a mode of reduced activity called the idle mode, in which mode the CPU is frozen, while the RAM, timers, etcetera continue functioning, and a mode of further reduced activity, called the stop mode, in which mode the RAM contents are saved but the oscillator is frozen causing all other chip functions to be inoperative.
- the energy consumed in the stop mode per unit time can be ignored with respect to the energy consumed in the idle mode.
- the idle mode as well as the stop mode are activated by software.
- the invention is characterized in that the data processing apparatus further comprises: - switching means, interconnected between said second power supply terminal means and said oscillator means, the switching means having a first control input for detecting an interrupt signal produced by said data receiving module for thereupon driving said switching means to an operating power transmitting state for said second supply terminal means and a second control input fed by said stop signal output for upong detection of a stop signal generated by said data processing element driving said switching means to a stand-by power transmitting state for said second supply terminal means; - a transition signal detector connected between said switching means and said reset signal input for upon detecting any transition from said stand-by power transmitting state to said operating power transmitting state generating a reset pulse, that has a trailing edge ocurring only after termination of said predetermined time interval .
- the invention may adjust the oscillator frequency at the most advantageous value, regarding the system's task and limitations.
- a direct consequence of freezing the oscillator in applications of a radio with a highly sensitive receiving part is to diminish interference.
- An eventual consequence of the invention is to realize a real-time processing in an economical way, as the clock frequency needs not be lowered.
- FIG. 1 is a first block diagram of a data processing apparatus according to the invention.
- data processing element 20 to be initially in the stop mode and oscillator 22 is stand-by on a power supply level too low to enable oscillating. In this state energy consumption of the apparatus is negligible.
- data receiving module 24 receives data from an environment and sends an interrupt pulse to a signal detector 26.
- signal detector 26 Upon receiving this pulse signal detector 26 gives off a signal to switching element 28, which thereupon provides full operating power to oscillator 22 via line 29.
- oscillator 22 starts oscillating while signal detector 30 detects a voltage change on line 29 and for that sends a pulse of predetermined width to the reset signal input of data processing element 20.
- the width of the reset pulse is chosen to be larger than the time necessary to reach stable oscillation plus the time necessary for the reset operationproper.
- Figure 2 shows an exemplary behaviour of the apparatus between two interrupts, lying a time T x apart.
- an interrupt which occurs at an instant A
- the oscillator switches from its stand-by, non-oscillating mode to its oscillating mode, while the data processing element is reset into an initial state. This operation is completed before the end of the reset pulse.
- the length of the reset pulse t o is larger than the settling time of the oscillator as the reset operation requires stable oscillations. In practice t o is made much larger than this settling time of the oscillator in order to stay within a safety range to guarantee a reset taking place under varying conditions (e.g. temperature drift). After termination of the reset pulse the data processing element becomes operating.
- the task of the data processing element takes a time t l .
- the data processing element goes into the stop mode under software control, whereby putting the oscillator into the stand-by mode via a stop signal, the data processing element requiring a time t o to settle in its stop mode.
- the time t o for reaching the initial state equals the time for reaching the stop mode.
- the apparatus is ready again to accept a next interrupt.
- Figure 3 comprises the formulae according to which the optimal oscillator frequency is determined in order to minimize energy consumption.
- formula (1) is defined the duty cycle of the system which is the fraction of the interval between two successive interrupts, in which the system is operating. As indicated this duty cycle is represented by a number between zero and one. Because the supplies voltages (V CC and V SS ) are kept constant, the averate current I av must be minimized.
- formula (2) is given the average amount of current passing through the data processing element between two successive interrupts. In the first instance the oscillator current is ignored because it is relatively small. This average current consists of a first part, present during operation, and a second part, present during the stop mode.
- the current I op necessary in the operating mode depends approximately linearly on the clock frequency f and also on parameters ⁇ and ⁇ , determined by thesilicon characteristics of the data processing element, within the frequency interval of interest and is stated by formula (3).
- the current in the stop mode I stop is a constant and very much smaller than the operating current and is given by formula (4).
- the duty cycle (1) too depends on the frequency via the duration of the period, in which the data processing element is in the operating mode, this period being a function of the frequency, the number of instructions N executed within this period and the average number of clock cycles per instruction C. The expression for this period in these terms is formula (5).
- formulae (1) and (5) determine a lower limit for the usable oscillator frequency, at which it is just possible to execute the give number of instructions between two successive interrupts. This lowest usable frequency is given in formula (6). Substituting (3) and (4) into (2), (5) into (1), and (1) thereafter into (2), gives formula (7).Minimizing expression (7) with respect to the frequency leads to the optimal frequency f opt of formula (8). Finally, the current consumed by the data processing element, clocked with frequency (8) in the operation mode, is the minimum, represented by formula (9). However, it must be checked whether this optimal frequency is permitted, since there exists a lower frequency limit, which is given by formula (6). This problem will be discussed in the light of Figure 4.
- An exemplary data processing apparatus is a portable telephone forming a part of a Portable Automatic Telephone System.
- a portable telephone comprises a modulator/demodulator connected to a microcontroller, e.g. a PCB80C31 (Philips Data Handbook IC14N, 1985, pp. 187-213).
- the most profitable oscillator frequency is equal to 3.5 MHz, as can be calculated with the formulae in Figure 3.
- the invention yields profit in that the frozen oscillator cannot cause interference with identification bits in each information packet.
- the receiving part of the data processing apparatus may be constructed as a highly sensitive receiver.
- the frequency must lie in the frequency interval given by formulae (10) in case 1), or in the frequency interval of formulae (11) in case 2) as can readily be deduced from formulae (6) to (9).
- formula (13) the average current consumption is given by formula (13), in which formula is substituted the (approximate) current - against-frequency - characteristic of the data processing element in the idle mode (12) within the frequency interval of interest.
- Optimizing formula (13) with respect to the frequency delivers the minimum current consumption (14).
- This minimum current consumption (14) when the idle mode is used exceeds the minimum current consumption (9) using the stop mode.
- the clock frequency For keeping the energy consumption of the data processing element, when switched between the operating mode and the stop mode, below the energy consumption of the data processing element that can be attained by switching between the operating mode and the idle mode, the clock frequency must lie in the frequency interval of expression (15) as can be calculated by using formulae (7) and (14).
- Figure 5 pictures a circuit diagram of the oscillator, switching element and the second signal detector, used in the preferred embodiment of the invention according to the block diagram of Figure 1.
- the switching element comprises a reset-set-flipflop 50, pnp-transistor 52, resistor 54 and a signal detecting circuit 56.
- the oscillator 58 is chosen to be a Colpitts-oscillator for its excellent frequency stability, short response time and high oscillating frequency.
- the output signal is buffered by amplifier A1.
- the signal detector 60 is a differentiating circuit, having a diode D1 connected to its output, in order to reset the data processing element only when the detector senses an upgoing voltage change.
- Resistor 54 is chosen to be of high resistance to supply the oscillator 58 with a stand-by current in its stand-by mode, in order to prevent the parasitic capacitor C p between the control electrode and collector of transistor T2 in the oscillator 58 from discharging completely, this capacitor being charged while the oscillator is in the operating mode. In this way the settling time of the oscillator is kept sufficiently low.
- the reset input of flipflop 50 is connected to the output terminal of the first signal detector 26 in Figure 1, the set input of flipflop 50 is connected to the stop signal output of the data processing element 20 via a signal detecting circuit 56, which takes care of supplying the flipflop with a set signal of the right polarity and duration.
- the data processing apparatus can be made accessible for other than the previously mentioned interrupt signal for generating a reset of the data processing element e.g. by feeding the reset terminal of flip-flop 50 via an OR-gate (not shown).
- Amplifiers A1, A2 and A3 are fully supplied via transistor 52 when the oscillator needs operating and are kept on a small stand-by supply when theoscillator is in the stand-by mode.
- a second interrupt following immediately a first interrupt is harmless because of the input/output characteristics of reset-set-flipflop 50.
- FIG 6 is given a second block diagram of a data processing apparatus according to the invention.
- This second block diagram differs from that of Figure 1 in having three data receiving modules for receiving data from an environment 70, 72 and 74 instead of one, a selection device 76 connected between these data receiving modules and the data input of data processing element 78, and a clock 82, comprising three different oscillator circuits instead of one oscillator as is the case in Figure 1.
- an interrupt signal from one data receiving module for example data receiving module 70
- eselection device 76 conencts the data output of data receiving module 70 to the data input of data processing element 78, feeds this interrupt signal to signal detector 80 and selects in clock 82 an oscillator circuit, thereby disabling transmission of data or of interrupt signals from data receiving modules 72 and 74 to said data input or signal detector 80 respectively.
- the selected oscillator circuit comprises a resonance circuit which fixes the adapted clock frequency of the pulses, fed into the clock input of data processing element 78.
- the adapted clock frequencies are determined as is described with the help of Figures 3 and 4 and depend among others on the amount of instructions to be executed, required by the data throughput of the data receiving modules 70.
- data processing element 78 After execution of the instructions required by data receiving module 70, data processing element 78 sends a stop signal to selection device 76 via signal detector 92, which thereby disconnects the data output of data receiving module 70 from said data input and restores the connection from the interrupt signal outputs of data receiving modules 72 and 74 to signal detector 80.
- the operation of the apparatus of Figure 6 is further analogous to that of the apparatus of Figure 1.
- FIG 7 a hardware implementation is given of the selection device 76 and clock circuit 82 in Figure 6.
- the embodiment of the invention in Figure 6 comprises only three data receiving modules, extension to more data receiving modules is straightforward. Therefore the former case will be examined.
- Data receiving modules 70, 72 and 74 in Figure 6 have their data outputs connected to the data input of data processing element 78 via transistors 228, 230 and 232 respectively, and have their interrupt signal outputs connected to the reset terminals of reset-set-latches 222, 224 and 226 via two transistors in series 210/212, 214/216 and 218/220 respectively.
- each reset-set-latch is connected to the stop signal output of data processing element 78 via a signal detector 92.
- the first latch output terminals of reset-set-latches 222, 224 and 226 are connected to the control electrode of transistors 228, 230 and 232 respectively.
- the second latch output terminal of reset-set-latch 222 is connected to the control electrode of transistors 214 and 218, the second latch output terminal of reset-set-latch 224 is connected to the control electrode of transistor 210 and 220 and the second latch output terminal of reset-set-latch 226 is connected to the control electrode of transistors 212 and 216.
- the reset terminal of each reset-set-latch is connected to an input terminal of an OR-gate 23.
- the output terminal of said OR-gate is connected to the input of signal detector 80 in Figure 6.
- the first latch output terminals of reset-set-latches 22, 224 and 226 are connected to the control electrode of transistors 238, 240 and 242
- transistor 228 is rendered conducting thereby connecting the data output of data receiving module 70 to said data input and transistors 214 and 218 are blocked, thereby preventing reset-set-latches 224 and 226 from switching.
- signal detector 80 receives via OR-gate 234 the interrupt signal and an oscillator circuit, comprising resonant circuit 244, is selected in clock circuit.
- reset-set-latch 222 is switched back, which leads to the blocking of transistors 228 and 238 and the conducting of transistors 214 and 218. Then the apparatus is ready again to manage a new interrupt signal.
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Power Sources (AREA)
Abstract
Description
- The invention relates to a data processing apparatus comprising:
- a data processing element, having an operating mode and a stop mode, said element comprising a data input a first data output, a reset signal input, a clock input a stop signal output and first power supply terminal means;
- oscillator means for feeding said clock input with clock pulses, said oscillator means having second power supply terminal means;
- a data receiving module for receiving external data, said module having a second data output connected to the data input;
wherein said data processing element has reset means for under combined control of a series of clock pulses and a reset signal on said reset input attaining an initial state within a predetermined line interval, the data processing apparatus being suited for economically consuming energy. - Reducing energy consumption is of interest in environments of limited available power, e.g. in implanted medical devices, portable equipment or space satellites and in devices in which energy dissipation should be limited, e.g. in VLSI circuits.
- A first method for reducing energy consumption in a clocked data processing apparatus, designed in a low-power technology, would be to lower the frequency of the clock as far as possbile regarding the required data throughput. Problems then occur, in that DC-current paths, which can be hidden in the design of the data processing element, will be open for a longer period, thereby partially undoing this reduction, and also in that real-time processing may be no longer possible.
- A second method for reducing energy consumption would be to use a data processing element, having an operating mode and a mode of reduced activity, and to switch between these modes, keeping the element in the latter mode as long as no operating is required, in which mode the consuming of energy is less than in the former mode. A data processing element having an operating mode and modes of reduced activity is for example the single-chip 8-bit microcontroller PCB80C31, (Philips Data Handbook IC14N, 1985, pp.187-213). This element has a mode of reduced activity called the idle mode, in which mode the CPU is frozen, while the RAM, timers, etcetera continue functioning, and a mode of further reduced activity, called the stop mode, in which mode the RAM contents are saved but the oscillator is frozen causing all other chip functions to be inoperative. The energy consumed in the stop mode per unit time can be ignored with respect to the energy consumed in the idle mode. The idle mode as well as the stop mode are activated by software.
- It is an object of the present invention to reduce the energy consumption by using a data processing element, having an operating mode and a stop mode, in which latter mode all element functions are inoperative but memory contents are saved, and connected to an oscillator, which oscillator is frozen in a stand-by mode while the data processing element is in the stop mode and which oscillator is operative while the data processing element is in the operating mode.
- The invention is characterized in that the data processing apparatus further comprises:
- switching means, interconnected between said second power supply terminal means and said oscillator means, the switching means having a first control input for detecting an interrupt signal produced by said data receiving module for thereupon driving said switching means to an operating power transmitting state for said second supply terminal means and a second control input fed by said stop signal output for upong detection of a stop signal generated by said data processing element driving said switching means to a stand-by power transmitting state for said second supply terminal means;
- a transition signal detector connected between said switching means and said reset signal input for upon detecting any transition from said stand-by power transmitting state to said operating power transmitting state generating a reset pulse, that has a trailing edge ocurring only after termination of said predetermined time interval . - The invention may adjust the oscillator frequency at the most advantageous value, regarding the system's task and limitations.
- A direct consequence of freezing the oscillator in applications of a radio with a highly sensitive receiving part (e.g. a MODEM) is to diminish interference.
- An eventual consequence of the invention is to realize a real-time processing in an economical way, as the clock frequency needs not be lowered.
- The invention will be described with reference to some Figures.
- Figure 1 shows a first block diagram of a data processing apparatus according to the invention.
- Figure 2 represents the behaviour of the apparatus of Figure 1 with time.
- Figure 3a, 3b, 3c comprise the formulae according to which the optimal oscillator frequency can be determined.
Equations (1) through (9) determine the optimal oscillator frequency.
Equations (10) and (11) determine a frequency interval in which the oscillator frequency must lie in order to have an energy consumption higher by a fraction δ than the minimum. One can choose δ to be equal to, say, 10%, 50% or another value depending on one's preference.
Equations (12) through (15) determine a frequency interval in which the oscillator frequency must lie in order to keep the energy consumption, when the data processing element is switched between the operating mode and the stop mode, below the minimum of the energy consumption, when switching occurs between the operating mode and the idle mode. - Figure 4 is a typical graph of the average current consumed by the apparatus between two successive interrupts as a function of the frequency, according to the formulae of Figure 3.
- Figure 5 pictures a circuit diagram of an oscillator, switching means and second signal detector, used in the preferred embodiment of the invention according to Figure 1.
- Figure 6 gives a second block diagram of a data processing apparatus according to the invention.
- Figure 7 is a hardware implementation of a preferred exemplary embodiment of the invention according to Figure 6.
- Figure 1 is a first block diagram of a data processing apparatus according to the invention. We assume
data processing element 20 to be initially in the stop mode andoscillator 22 is stand-by on a power supply level too low to enable oscillating. In this state energy consumption of the apparatus is negligible. At a certain momentdata receiving module 24 receives data from an environment and sends an interrupt pulse to asignal detector 26. Upon receiving thispulse signal detector 26 gives off a signal to switchingelement 28, which thereupon provides full operating power tooscillator 22 vialine 29. Thereuponoscillator 22 starts oscillating whilesignal detector 30 detects a voltage change online 29 and for that sends a pulse of predetermined width to the reset signal input ofdata processing element 20. The width of the reset pulse is chosen to be larger than the time necessary to reach stable oscillation plus the time necessary for the reset operationproper. After termination of the reset pulse,data processing element 20 reads the data fromdata receiving module 24, processes the data as far as necessary and accordingly writes out data to data controlledmodule 32. When this task has been performed,data processing element 20 goes into the stop mode, which is activated by software, and sends thereby a stop signal viasignal detector 25 to switchingelement 28, which thereupon switches the power supply tooscillator 22 from full supply to a stand-by supply. - Figure 2 shows an exemplary behaviour of the apparatus between two interrupts, lying a time Tx apart. As soon as an interrupt is detected, which occurs at an instant A, the oscillator switches from its stand-by, non-oscillating mode to its oscillating mode, while the data processing element is reset into an initial state. This operation is completed before the end of the reset pulse. The length of the reset pulse to is larger than the settling time of the oscillator as the reset operation requires stable oscillations. In practice to is made much larger than this settling time of the oscillator in order to stay within a safety range to guarantee a reset taking place under varying conditions (e.g. temperature drift). After termination of the reset pulse the data processing element becomes operating. The task of the data processing element takes a time tl. At the end of this time interval tl the data processing element goes into the stop mode under software control, whereby putting the oscillator into the stand-by mode via a stop signal, the data processing element requiring a time to to settle in its stop mode. For conversion it is assumed that the time to for reaching the initial state equals the time for reaching the stop mode. At instant B the apparatus is ready again to accept a next interrupt.
- Figure 3 comprises the formulae according to which the optimal oscillator frequency is determined in order to minimize energy consumption. In formula (1) is defined the duty cycle of the system which is the fraction of the interval between two successive interrupts, in which the system is operating. As indicated this duty cycle is represented by a number between zero and one. Because the supplies voltages (VCC and VSS) are kept constant, the averate current Iav must be minimized. In formula (2) is given the average amount of current passing through the data processing element between two successive interrupts. In the first instance the oscillator current is ignored because it is relatively small. This average current consists of a first part, present during operation, and a second part, present during the stop mode. The current Iop necessary in the operating mode depends approximately linearly on the clock frequency f and also on parameters α and β, determined by thesilicon characteristics of the data processing element, within the frequency interval of interest and is stated by formula (3). The current in the stop mode Istop is a constant and very much smaller than the operating current and is given by formula (4). The duty cycle (1) too depends on the frequency via the duration of the period, in which the data processing element is in the operating mode, this period being a function of the frequency, the number of instructions N executed within this period and the average number of clock cycles per instruction C. The expression for this period in these terms is formula (5). As the duty cycle (1) equals one or is smaller than one, formulae (1) and (5) determine a lower limit for the usable oscillator frequency, at which it is just possible to execute the give number of instructions between two successive interrupts. This lowest usable frequency is given in formula (6). Substituting (3) and (4) into (2), (5) into (1), and (1) thereafter into (2), gives formula (7).Minimizing expression (7) with respect to the frequency leads to the optimal frequency fopt of formula (8). Finally, the current consumed by the data processing element, clocked with frequency (8) in the operation mode, is the minimum, represented by formula (9). However, it must be checked whether this optimal frequency is permitted, since there exists a lower frequency limit, which is given by formula (6). This problem will be discussed in the light of Figure 4.
- An exemplary data processing apparatus is a portable telephone forming a part of a Portable Automatic Telephone System. Such a portable telephone comprises a modulator/demodulator connected to a microcontroller, e.g. a PCB80C31 (Philips Data Handbook IC14N, 1985, pp. 187-213). Typical values for some quantitites characterizing a PCB80C31 - microcontroller are: α = 1.3x10⁻⁹Asec; β = 8x10⁻⁴A; ϑ=5x10⁻⁵A; to=10⁻³sec; C = 20. If information packets enter the telephone every T = 0.5 sec, each packet requiring an amount of N = 2000 instructions to be executed, the most profitable oscillator frequency is equal to 3.5 MHz, as can be calculated with the formulae in Figure 3. In this application the invention yields profit in that the frozen oscillator cannot cause interference with identification bits in each information packet. As a consequence the receiving part of the data processing apparatus may be constructed as a highly sensitive receiver.
- Figure 4 is a typical graph of the average current consumed by the data processing element between two successive interrupts as a function of the clock frequency, this information being comprised in formula (7) and being of the form:
Iav = Kf + + L, K, L, M are constants specified in formulae (1) through (5).
We distinguish two cases: - 1) The lowest usable frequency, as given in formula (6), is smaller than or equal to the optical frequency of formula (8).
- 2) The lowest usable frequency (6) is larger than or equal to the optimal frequency (8).
- To obtain a low energy consumption within a fraction δ of the attainable minimum in practice, say 10%, the frequency must lie in the frequency interval given by formulae (10) in case 1), or in the frequency interval of formulae (11) in case 2) as can readily be deduced from formulae (6) to (9). When, instead of switching between the stop mode and the operating mode, the switching between the idle mode and the operating mode is used, the settling time, the amount of instructions to be executed and the interrupt rate being the same, the average current consumption is given by formula (13), in which formula is substituted the (approximate) current - against-frequency - characteristic of the data processing element in the idle mode (12) within the frequency interval of interest. Typical values for the parameters characteristic for a PCB80C31 microcontroller are: Σ =2.5x10⁻¹⁰Asec; λ =7x10⁻⁴A. Optimizing formula (13) with respect to the frequency delivers the minimum current consumption (14). This minimum current consumption (14) when the idle mode is used exceeds the minimum current consumption (9) using the stop mode. For keeping the energy consumption of the data processing element, when switched between the operating mode and the stop mode, below the energy consumption of the data processing element that can be attained by switching between the operating mode and the idle mode, the clock frequency must lie in the frequency interval of expression (15) as can be calculated by using formulae (7) and (14).
- Figure 5 pictures a circuit diagram of the oscillator, switching element and the second signal detector, used in the preferred embodiment of the invention according to the block diagram of Figure 1.
- In Figure 5 the switching element comprises a reset-set-
flipflop 50, pnp-transistor 52,resistor 54 and asignal detecting circuit 56. Theoscillator 58 is chosen to be a Colpitts-oscillator for its excellent frequency stability, short response time and high oscillating frequency. The output signal is buffered by amplifier A₁. Thesignal detector 60 is a differentiating circuit, having a diode D₁ connected to its output, in order to reset the data processing element only when the detector senses an upgoing voltage change.Resistor 54 is chosen to be of high resistance to supply theoscillator 58 with a stand-by current in its stand-by mode, in order to prevent the parasitic capacitor Cp between the control electrode and collector of transistor T₂ in theoscillator 58 from discharging completely, this capacitor being charged while the oscillator is in the operating mode. In this way the settling time of the oscillator is kept sufficiently low. The reset input offlipflop 50 is connected to the output terminal of thefirst signal detector 26 in Figure 1, the set input offlipflop 50 is connected to the stop signal output of thedata processing element 20 via asignal detecting circuit 56, which takes care of supplying the flipflop with a set signal of the right polarity and duration. The data processing apparatus can be made accessible for other than the previously mentioned interrupt signal for generating a reset of the data processing element e.g. by feeding the reset terminal of flip-flop 50 via an OR-gate (not shown). Amplifiers A₁, A₂ and A₃ are fully supplied viatransistor 52 when the oscillator needs operating and are kept on a small stand-by supply when theoscillator is in the stand-by mode. A second interrupt following immediately a first interrupt is harmless because of the input/output characteristics of reset-set-flipflop 50. - In Figure 6 is given a second block diagram of a data processing apparatus according to the invention. This second block diagram differs from that of Figure 1 in having three data receiving modules for receiving data from an
environment selection device 76 connected between these data receiving modules and the data input ofdata processing element 78, and aclock 82, comprising three different oscillator circuits instead of one oscillator as is the case in Figure 1. - Upon reception of an interrupt signal from one data receiving module, for example data receiving module 70,
eselection device 76 conencts the data output of data receiving module 70 to the data input ofdata processing element 78, feeds this interrupt signal to signaldetector 80 and selects inclock 82 an oscillator circuit, thereby disabling transmission of data or of interrupt signals fromdata receiving modules signal detector 80 respectively. The selected oscillator circuit comprises a resonance circuit which fixes the adapted clock frequency of the pulses, fed into the clock input ofdata processing element 78. The adapted clock frequencies are determined as is described with the help of Figures 3 and 4 and depend among others on the amount of instructions to be executed, required by the data throughput of the data receiving modules 70. - After execution of the instructions required by data receiving module 70,
data processing element 78 sends a stop signal toselection device 76 viasignal detector 92, which thereby disconnects the data output of data receiving module 70 from said data input and restores the connection from the interrupt signal outputs ofdata receiving modules detector 80. The operation of the apparatus of Figure 6 is further analogous to that of the apparatus of Figure 1. - In Figure 7 a hardware implementation is given of the
selection device 76 andclock circuit 82 in Figure 6. Although the embodiment of the invention in Figure 6 comprises only three data receiving modules, extension to more data receiving modules is straightforward. Therefore the former case will be examined. -
Data receiving modules data processing element 78 viatransistors latches series 210/212, 214/216 and 218/220 respectively. - The set terminal of each reset-set-latch is connected to the stop signal output of
data processing element 78 via asignal detector 92. The first latch output terminals of reset-set-latches transistors latch 222 is connected to the control electrode oftransistors latch 224 is connected to the control electrode oftransistor latch 226 is connected to the control electrode oftransistors signal detector 80 in Figure 6. The first latch output terminals of reset-set-latches transistors - We assume the
data processing element 78 in Figure 6 initially to be in the stop mode, which mode determines the initial state of reset-set-latches initial state transistors transistors 210/212, 214/216 and 218/220 are conducting. At a certain moment one of the data receiving modules sends an interrupt signal, for instance data receiving module 70. This signal passes throughtransistors 210/212 and switches the state of reset-set-latch 222. Thereupontransistor 228 is rendered conducting thereby connecting the data output of data receiving module 70 to said data input andtransistors latches signal detector 80 receives viaOR-gate 234 the interrupt signal and an oscillator circuit, comprisingresonant circuit 244, is selected in clock circuit. As soon as the data processing element sends a stop signal, reset-set-latch 222 is switched back, which leads to the blocking oftransistors transistors
In case 1) the most profitable frequency is equal to the optimal frequency of formula (8) in order to have a minimum energy consumption.
In case 2) the most profitable frequency at which the energy consumption is at a minimum equals the lowest usable frequency. For case 1) the lowest usable frequency lies on the left of the optical frequency in Figure 4 and is marked with a single asterisk, whereas for case 2) the lowest usable frequency lies on the right of the optimal freuqency and is marked with double asterisks.
Claims (13)
- a data processing element, having an operating mode and a stop mode, said element comprising a data input a first data output, a reset signal input, a clock input a stop signal output and first power supply terminal means;
- oscillator means for feeding said clock input with clock pulses, said oscillator means having second power supply terminal means;
- a data receiving module for receiving external data, said module having a second data output connected to the data input;
wherein said dataprocessing element has reset means for under combined control of a series of clock pulses and a reset signal on said reset input attaining an initial state within a predetermined time interval, characterized in that the data processing apparatus further comprises:
- switching means, interconnected between said second power supply terminal means and said oscillator means, the switching means having a first control input for detecting an interrupt signal produced by said data receiving module for thereupon driving said switching means to an operating power transmitting state for said second supply terminal means and a second control input fed by said stop signal output for upon detection of a stop signal generated by said data processing element driving said switching means to a stand-by power transmitting state for said second supply terminal means;
- a transition signal detector connected betweensaid switching means and said reset signal input for upon detecting any transition from said stand-by power transmitting state to said operating power transmitting state generating a reset pulse, that has a trailing edge occurring only after termination of said predetermined time interval.
wherein
X ≈ (((β - λ) (ΣT+2toα)NC)½)/2toα+(λT-NC Σ)/4to
P ≈ ((NCβ)/(2toα))½ + 0.1 . {((NCβ)/(2toα))½ + β/2α + NC/4to α + ϑT/4toα}
R≈NC/2T + β T/4αto+ 0.1 (NC/4to + βT/4αto)
- a selection means fed in parallel by said second data output and fed in parallel by said interrupt signal outputs,
said selection means having:
- first gating means for gating a first received interrupt signal to said first control input;
- second gating means for gating data sssociated to said first received interrupt signal to said data processing element;
- disabling means for upon reception of said first received interrupt signal disabling said first and second gating means for gating any interrupt signal or data from another data receiving module than the one generating said first received interrupt signal;
- enabling means connected to said second control input for upon reception of said stop signal reenabling said first and second gating means.
- a number of j reset-set-latches, each having its set terminal connected to said stop-signal detector;
- a number of j AND-gating means, each having (j-1) gate inputs and connecting a respective interrupt signal output to an associated reset terminal;
- a number of j interface gating means, each connecting a respective second data output to the data input and having a blocking state, a passing state and a state control input connected to a first output terminal of an associated reset-set-latch, for upon reception of a blocking-signal being driven go the blocking state and upon reception of a pass-signal being driven to the passing state;
- a j-input OR-gating means fed by said j reset terminals and feeding the interrupt-signal detector;
wherein AND-gating means of rank number k, 1 ≦ k ≦ j, connecting data receiving module number k to reset-set-latch number k, has its (j-1) gate input connected to respective second output terminals of reset-set-latches with numbers m ≠ k, 1 ≦ m ≦ j.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8620056 | 1986-08-18 | ||
GB08620056A GB2194082A (en) | 1986-08-18 | 1986-08-18 | Data processing apparatus with energy saving clocking device |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0256594A2 true EP0256594A2 (en) | 1988-02-24 |
EP0256594A3 EP0256594A3 (en) | 1989-10-25 |
EP0256594B1 EP0256594B1 (en) | 1992-07-22 |
Family
ID=10602863
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP87201486A Expired - Lifetime EP0256594B1 (en) | 1986-08-18 | 1987-08-05 | Data processing apparatus with energy saving clocking device |
Country Status (6)
Country | Link |
---|---|
US (1) | US4823292A (en) |
EP (1) | EP0256594B1 (en) |
JP (1) | JPS6349915A (en) |
AU (1) | AU608528B2 (en) |
DE (1) | DE3780531T2 (en) |
GB (1) | GB2194082A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0343528A2 (en) * | 1988-05-21 | 1989-11-29 | Fujitsu Limited | Mobile telephone terminal |
EP0391543A2 (en) * | 1989-04-06 | 1990-10-10 | Advanced Micro Devices, Inc. | Microprocessor clock |
EP0407270A1 (en) * | 1989-07-07 | 1991-01-09 | STMicroelectronics S.A. | Integrated circuit with variable clock frequency |
EP0446519A2 (en) * | 1990-03-13 | 1991-09-18 | Mitsubishi Denki Kabushiki Kaisha | Noncontact integrated circuit card |
FR2663764A1 (en) * | 1990-06-22 | 1991-12-27 | Mitsubishi Electric Corp | CARD WITHOUT CONTACT. |
EP0499178A1 (en) * | 1991-02-08 | 1992-08-19 | Nec Corporation | System clock switching mechanism for microprocessor |
US5274221A (en) * | 1990-06-22 | 1993-12-28 | Mitsubishi Denki Kabushiki Kaisha | Non-contact integrated circuit card |
WO1999031840A2 (en) * | 1997-12-16 | 1999-06-24 | Koninklijke Philips Electronics N.V. | Electronic circuit with a clock switch |
DE10009683A1 (en) * | 2000-02-29 | 2001-08-30 | Nokia Mobile Phones Ltd | Interrupting communications unit quiescent state, especially in radio communications system, involves reducing time remaining to next activation to time sufficient for activation |
Families Citing this family (48)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2063413C (en) * | 1989-06-30 | 2000-08-15 | Leroy D. Harper | Computer power management system |
US5222239A (en) * | 1989-07-28 | 1993-06-22 | Prof. Michael H. Davis | Process and apparatus for reducing power usage microprocessor devices operating from stored energy sources |
US5218704A (en) | 1989-10-30 | 1993-06-08 | Texas Instruments | Real-time power conservation for portable computers |
US6158012A (en) * | 1989-10-30 | 2000-12-05 | Texas Instruments Incorporated | Real-time power conservation and thermal management for computers |
US5201059A (en) * | 1989-11-13 | 1993-04-06 | Chips And Technologies, Inc. | Method for reducing power consumption includes comparing variance in number of time microprocessor tried to react input in predefined period to predefined variance |
US5396635A (en) * | 1990-06-01 | 1995-03-07 | Vadem Corporation | Power conservation apparatus having multiple power reduction levels dependent upon the activity of the computer system |
GB2246455A (en) * | 1990-07-23 | 1992-01-29 | Philips Electronic Associated | Altering the rate at which digital circuitry operates |
FI88657C (en) * | 1991-02-12 | 1993-06-10 | Nokia Mobile Phones Ltd | Foerfarande Foer att minska stroemfoerbrukningen i en mobil telefon |
US5303171A (en) * | 1992-04-03 | 1994-04-12 | Zenith Data Systems Corporation | System suspend on lid close and system resume on lid open |
US5446904A (en) | 1991-05-17 | 1995-08-29 | Zenith Data Systems Corporation | Suspend/resume capability for a protected mode microprocessor |
US5394527A (en) * | 1991-05-17 | 1995-02-28 | Zenith Data Systems Corporation | Method and apparatus facilitating use of a hard disk drive in a computer system having suspend/resume capability |
US5652890A (en) * | 1991-05-17 | 1997-07-29 | Vantus Technologies, Inc. | Interrupt for a protected mode microprocessor which facilitates transparent entry to and exit from suspend mode |
EP1413946A3 (en) * | 1991-05-17 | 2005-12-21 | Packard Bell NEC, Inc. | Computer system having a reduced power control circuit |
US5842029A (en) * | 1991-10-17 | 1998-11-24 | Intel Corporation | Method and apparatus for powering down an integrated circuit transparently and its phase locked loop |
GB2260631B (en) * | 1991-10-17 | 1995-06-28 | Intel Corp | Microprocessor 2X core design |
US5935253A (en) * | 1991-10-17 | 1999-08-10 | Intel Corporation | Method and apparatus for powering down an integrated circuit having a core that operates at a speed greater than the bus frequency |
GB2264794B (en) * | 1992-03-06 | 1995-09-20 | Intel Corp | Method and apparatus for automatic power management in a high integration floppy disk controller |
US6193422B1 (en) | 1992-04-03 | 2001-02-27 | Nec Corporation | Implementation of idle mode in a suspend/resume microprocessor system |
US5423045A (en) * | 1992-04-15 | 1995-06-06 | International Business Machines Corporation | System for distributed power management in portable computers |
US5287292A (en) * | 1992-10-16 | 1994-02-15 | Picopower Technology, Inc. | Heat regulator for integrated circuits |
US5473767A (en) * | 1992-11-03 | 1995-12-05 | Intel Corporation | Method and apparatus for asynchronously stopping the clock in a processor |
US5392437A (en) * | 1992-11-06 | 1995-02-21 | Intel Corporation | Method and apparatus for independently stopping and restarting functional units |
US5586332A (en) * | 1993-03-24 | 1996-12-17 | Intel Corporation | Power management for low power processors through the use of auto clock-throttling |
US7216064B1 (en) | 1993-09-21 | 2007-05-08 | Intel Corporation | Method and apparatus for programmable thermal sensor for an integrated circuit |
SG48805A1 (en) * | 1994-02-04 | 1998-05-18 | Intel Corp | Method and apparatus for control of power consumption in a computer system |
US5754436A (en) * | 1994-12-22 | 1998-05-19 | Texas Instruments Incorporated | Adaptive power management processes, circuits and systems |
US5834956A (en) | 1995-12-29 | 1998-11-10 | Intel Corporation | Core clock correction in a 2/N mode clocking scheme |
US5821784A (en) * | 1995-12-29 | 1998-10-13 | Intel Corporation | Method and apparatus for generating 2/N mode bus clock signals |
US5802132A (en) * | 1995-12-29 | 1998-09-01 | Intel Corporation | Apparatus for generating bus clock signals with a 1/N characteristic in a 2/N mode clocking scheme |
US5826067A (en) * | 1996-09-06 | 1998-10-20 | Intel Corporation | Method and apparatus for preventing logic glitches in a 2/n clocking scheme |
US5862373A (en) * | 1996-09-06 | 1999-01-19 | Intel Corporation | Pad cells for a 2/N mode clocking scheme |
US5987614A (en) * | 1997-06-17 | 1999-11-16 | Vadem | Distributed power management system and method for computer |
US6115823A (en) | 1997-06-17 | 2000-09-05 | Amphus, Inc. | System and method for task performance based dynamic distributed power management in a computer system and design method therefor |
US6928559B1 (en) * | 1997-06-27 | 2005-08-09 | Broadcom Corporation | Battery powered device with dynamic power and performance management |
DE19733530C2 (en) * | 1997-08-02 | 2003-10-09 | Philips Intellectual Property | mobile device |
JP2000122747A (en) | 1998-10-12 | 2000-04-28 | Nec Corp | Device and method for controlling digital signal processing part |
US6665802B1 (en) | 2000-02-29 | 2003-12-16 | Infineon Technologies North America Corp. | Power management and control for a microcontroller |
US7822967B2 (en) * | 2000-09-27 | 2010-10-26 | Huron Ip Llc | Apparatus, architecture, and method for integrated modular server system providing dynamically power-managed and work-load managed network devices |
USRE40866E1 (en) | 2000-09-27 | 2009-08-04 | Huron Ip Llc | System, method, and architecture for dynamic server power management and dynamic workload management for multiserver environment |
US7228441B2 (en) | 2000-09-27 | 2007-06-05 | Huron Ip Llc | Multi-server and multi-CPU power management system and method |
US7552350B2 (en) | 2000-09-27 | 2009-06-23 | Huron Ip Llc | System and method for activity or event base dynamic energy conserving server reconfiguration |
US7032119B2 (en) * | 2000-09-27 | 2006-04-18 | Amphus, Inc. | Dynamic power and workload management for multi-server system |
US20030196126A1 (en) * | 2002-04-11 | 2003-10-16 | Fung Henry T. | System, method, and architecture for dynamic server power management and dynamic workload management for multi-server environment |
US20060248360A1 (en) * | 2001-05-18 | 2006-11-02 | Fung Henry T | Multi-server and multi-CPU power management system and method |
US7111179B1 (en) | 2001-10-11 | 2006-09-19 | In-Hand Electronics, Inc. | Method and apparatus for optimizing performance and battery life of electronic devices based on system and application parameters |
US7388248B2 (en) * | 2004-09-01 | 2008-06-17 | Micron Technology, Inc. | Dielectric relaxation memory |
WO2009138953A1 (en) * | 2008-05-13 | 2009-11-19 | Nxp B.V. | Power manager and method for managing power |
US8634914B2 (en) * | 2012-01-27 | 2014-01-21 | Medtronic, Inc. | Pacemaker event queue to control device processor operating power |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2080585A (en) * | 1980-07-22 | 1982-02-03 | Tokyo Shibaura Electric Co | Semiconductor integrated circuit with reduced power consumption |
US4317181A (en) * | 1979-12-26 | 1982-02-23 | Texas Instruments Incorporated | Four mode microcomputer power save operation |
GB2110441A (en) * | 1981-11-27 | 1983-06-15 | Wright Electronics | Power supply control |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU3117584A (en) * | 1983-07-28 | 1985-01-31 | Dulmison Pty. Limited | Battery conservation circuit |
US4649373A (en) * | 1983-08-10 | 1987-03-10 | International Business Machines Corporation | Powered conservation system in battery powered keyboard device including a microprocessor |
CA1223667A (en) * | 1984-07-26 | 1987-06-30 | Mark C. Loessel | Microcomputer clock circuit |
JPS6152722A (en) * | 1984-08-22 | 1986-03-15 | Nippon Data General Kk | Power econimizing system |
-
1986
- 1986-08-18 GB GB08620056A patent/GB2194082A/en not_active Withdrawn
-
1987
- 1987-08-05 DE DE8787201486T patent/DE3780531T2/en not_active Expired - Fee Related
- 1987-08-05 EP EP87201486A patent/EP0256594B1/en not_active Expired - Lifetime
- 1987-08-17 AU AU77124/87A patent/AU608528B2/en not_active Ceased
- 1987-08-17 US US07/086,440 patent/US4823292A/en not_active Expired - Lifetime
- 1987-08-18 JP JP62204953A patent/JPS6349915A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4317181A (en) * | 1979-12-26 | 1982-02-23 | Texas Instruments Incorporated | Four mode microcomputer power save operation |
GB2080585A (en) * | 1980-07-22 | 1982-02-03 | Tokyo Shibaura Electric Co | Semiconductor integrated circuit with reduced power consumption |
GB2110441A (en) * | 1981-11-27 | 1983-06-15 | Wright Electronics | Power supply control |
Non-Patent Citations (1)
Title |
---|
ELECTRONIC DESIGN, vol. 32, no. 20, October 1984, pages 185-191, Waseca, Minnesota, US; C.A. MROZ et al.: "Advanced clock controller cuts power needs, size of static CMOS systems" * |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0343528A3 (en) * | 1988-05-21 | 1992-03-04 | Fujitsu Limited | Mobile telephone terminal |
EP0343528A2 (en) * | 1988-05-21 | 1989-11-29 | Fujitsu Limited | Mobile telephone terminal |
EP0391543A2 (en) * | 1989-04-06 | 1990-10-10 | Advanced Micro Devices, Inc. | Microprocessor clock |
EP0391543A3 (en) * | 1989-04-06 | 1992-10-14 | Advanced Micro Devices, Inc. | Microprocessor clock |
FR2649506A1 (en) * | 1989-07-07 | 1991-01-11 | Sgs Thomson Microelectronics | INTEGRATED CIRCUIT WITH VARIABLE FREQUENCY CLOCK |
EP0407270A1 (en) * | 1989-07-07 | 1991-01-09 | STMicroelectronics S.A. | Integrated circuit with variable clock frequency |
EP0446519A2 (en) * | 1990-03-13 | 1991-09-18 | Mitsubishi Denki Kabushiki Kaisha | Noncontact integrated circuit card |
EP0446519A3 (en) * | 1990-03-13 | 1993-01-13 | Mitsubishi Denki Kabushiki Kaisha | Noncontact integrated circuit card |
FR2663764A1 (en) * | 1990-06-22 | 1991-12-27 | Mitsubishi Electric Corp | CARD WITHOUT CONTACT. |
US5274221A (en) * | 1990-06-22 | 1993-12-28 | Mitsubishi Denki Kabushiki Kaisha | Non-contact integrated circuit card |
EP0499178A1 (en) * | 1991-02-08 | 1992-08-19 | Nec Corporation | System clock switching mechanism for microprocessor |
WO1999031840A2 (en) * | 1997-12-16 | 1999-06-24 | Koninklijke Philips Electronics N.V. | Electronic circuit with a clock switch |
WO1999031840A3 (en) * | 1997-12-16 | 1999-08-19 | Koninkl Philips Electronics Nv | Electronic circuit with a clock switch |
DE10009683A1 (en) * | 2000-02-29 | 2001-08-30 | Nokia Mobile Phones Ltd | Interrupting communications unit quiescent state, especially in radio communications system, involves reducing time remaining to next activation to time sufficient for activation |
US6807408B2 (en) | 2000-02-29 | 2004-10-19 | Nokia Mobile Phones, Ltd. | Method for interrupting an idle state of a communication unit in a radio communication system |
Also Published As
Publication number | Publication date |
---|---|
JPS6349915A (en) | 1988-03-02 |
GB2194082A (en) | 1988-02-24 |
AU608528B2 (en) | 1991-04-11 |
GB8620056D0 (en) | 1986-10-01 |
EP0256594B1 (en) | 1992-07-22 |
DE3780531T2 (en) | 1993-02-25 |
EP0256594A3 (en) | 1989-10-25 |
AU7712487A (en) | 1988-02-25 |
US4823292A (en) | 1989-04-18 |
DE3780531D1 (en) | 1992-08-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0256594A2 (en) | Data processing apparatus with energy saving clocking device | |
EP0887990B1 (en) | Modem unit | |
US7761727B2 (en) | Micro-controller having USB control unit, MC unit and oscillating circuit commonly used by the USB control unit and the MC unit | |
US5212373A (en) | Non-contact ic card | |
RU2123236C1 (en) | High-frequency signal receiver | |
EP0560320B1 (en) | Clock generator | |
EP1324179B1 (en) | Dynamic power control in integrated circuits | |
US20090015233A1 (en) | Dynamic voltage transitions | |
GB2332763A (en) | Clock control type information processing apparatus | |
US5308968A (en) | Non-contact IC card which actively attenuates its resonance circuit as it receives data | |
US6026498A (en) | Clock signal generator circuit using a logical result of an output of a computer and a source clock to generate plurality of clock signals | |
EP0939495B1 (en) | Power saving system for an electronic portable device | |
EP0556597A1 (en) | An integrated circuit clock signal generator | |
EP0061461B1 (en) | Dual deadman timer circuit | |
EP0103755A2 (en) | CMOS single chip microprocessor | |
US6542726B2 (en) | Personal data assistant terminal with radio | |
EP0069484B1 (en) | Misoperation prevention circuit | |
US5926044A (en) | Clock switching device and method | |
US5812004A (en) | Current compensated clock for a microcircuit | |
US5754037A (en) | Digitally adaptive biasing regulator | |
JPS63172345A (en) | Input device for switch data | |
US6556057B2 (en) | Noise suppression circuitry and method | |
US6496078B1 (en) | Activating on-chip oscillator using ring oscillator | |
KR0184508B1 (en) | Control circuit of deep power down | |
EP0601539A2 (en) | Communication apparatus with low power consumption |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): CH DE FR GB IT LI SE |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): CH DE FR GB IT LI SE |
|
17P | Request for examination filed |
Effective date: 19900423 |
|
17Q | First examination report despatched |
Effective date: 19910424 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): CH DE FR GB IT LI SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19920722 |
|
REF | Corresponds to: |
Ref document number: 3780531 Country of ref document: DE Date of ref document: 19920827 |
|
ITTA | It: last paid annual fee | ||
ITF | It: translation for a ep patent filed | ||
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
ITPR | It: changes in ownership of a european patent |
Owner name: CAMBIO RAGIONE SOCIALE;PHILIPS ELECTRONICS N.V. |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PFA Free format text: PHILIPS ELECTRONICS N.V. |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: CD |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PFA Free format text: PHILIPS ELECTRONICS N.V. TRANSFER- KONINKLIJKE PHILIPS ELECTRONICS N.V. |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: CD |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20010824 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20010831 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20011015 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 20011114 Year of fee payment: 15 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20020805 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES Effective date: 20020831 Ref country code: CH Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES Effective date: 20020831 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20030301 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20020805 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20030430 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20050805 |